In the Graduate School of Education they use many different types of computers for many different things. Some staff will use their computers for typing long documents or letters; others may use them for creating PowerPoint presentations for lectures. In most organisations people will use their computers for similar things, but this isn’t the case in a university. There are a number of servers, and these all do different jobs. Each server is allocated a name, and this is unique over the whole campus. Most of the main file servers are held within the computer centre.
This allows them to rectify any problems that may arise if a server fails. All of the main servers work on dual hardware, and are hot swappable. This means that if one processor fails, or if one Random Access Memory slot fails, they are able to replace it, without any down time. The only time the server would go down would be in the case of a Power Supply Unit failing, and this can be fixed in a matter of minutes. In the computer centre all the computers are connected to a UPS and surge protection, in the form of sockets around the centre.
The surge protection will stop computer components being damaged due to a spike on the national grid, and the UPS will take over if there is a power cut. The UPS can provide power to the servers in the computer centre for a considerable amount of time. The smaller servers all have a small UPS, and these are configured to shut the server down if the power is off for any longer than 10 minutes. This means that all unsaved files are saved to the hard disk. In the Graduate School of Education there are 4 small servers, and these all do different jobs. There are 2 domain controllers.
The primary one is called Charlie and the backup is called Bravo. There are also 2 Macintosh database servers. One is a Mac G3 and the other is a PowerMac. In the main computer centre there are too many servers to mention here, and they are not all related to the Graduate School of Education. The ones they would use are the Student record server and the Library server. Both of these servers run on a telnet server (on port 23), and this allows secure access to them from inside the campus. All departments in the university have their own domain controllers. Domain controllers are usually rented or let to people by domain name hosting companies.
This sometimes has an advantage, if anything goes wrong, their technical support staff will rectify the problem, but in a university there are plenty of qualified people that can work with domain controllers. Because all the domain controllers are kept on campus, if JANET was to go down for some reason, for example, the cable was dug up; all the university domains would still work. So, a clumsy fore person does not check that the area they will be digging in is clear of cables, and they begin work. They hit the fibre optic cable and the university’s Internet connection goes down.